Electric production of carbon bisulphide



March 15, 1932. H. H. DOW 1,849,140

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Patented Mar. 15, 1932 HERBERT H. DOW, OF MIDLAND, MICHIGAN, ASSIGNOR TO THE DOW GHEJMEICAL COM- PANY, OF MIDLAND, MICHIGAN, A CORPORATION OF MICHIGAN ELECTRIC PRODUCTION OF CARBON BISULPHIDE Application filed November 30, 1926. Serial No. 151,810.

This invention relates more particularly to the manufacture of carbon bisulphide, and it is among the objects of the invention to provide improved procedure capable of a close range of control and efficient output. Other ob ects and advantages Wlll appear as the description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the features hereinafter fully described, and particularly pointed out 1n the claims, the following description and the annexed drawing setting forth in deta1l bu t one of the various ways of using the principle of the invention.

In said annexed drawing The sole figure is a vertical sectional v ew of one form of apparatus by means of which the invention may be carried out.

The reference character 1 in the drawing designates a retort or a vaporizer, heated in a suitable furnace, for example one fired by coal or oil, and having a trapped feed 1nlet 2. The vapor oiftake 3 leads to a chamber 4 which is provided with suitably closed or guarded inlets 5, 6, and .a clean-out door 7. Electrodes 8 are arranged one from each slde near the bottom of the chamber, and at the upper part of the chamber an ofitake 9 leads to a condenser.

In the practice of my improved process, the chamber 4 is supplied with carbon, best in the form of charcoal, and at the zone of the electrodes the mass is maintained at about red hot temperature by direct or alternating current passed therethrough, the current in the electrode zone being controlled to develop the temperature increment adequate for reaction between the c'harcoal and the sulphur vapor formed which is derived from the boiling sulphur in the vaporizer. The inlet 5 serves for the charging of the charcoal, and the inlet 6 allows the supplying of broken carbons through a partitioned compartment or chamber 10 directly to the electrode zone as may be desirable for local control of the resistance of the charge. For such broken carbon supply, any convenient or preferred source may be availed of, for instance waste or otherwise cheaply obtainable broken shapes or manufactured shapes. The denser conducting carbon lowers the resistance of the charcoal charge, particularly in the reaction zone where ash accumulates. Such conducting carbon is added in controlled amount as required, being more slowly consumed than the charcoal, and being liable to removal, at least in part, with the ash. The carbon bisulphide formed passes up and off through the connection 9 to the condenser.

In this manner the sulphur is made to carry its maximum practicable heat component, and the further temperature increment required for reaction is supplied direct in the carbon at the reaction zone in a manner to avoid the heat losses and inefliciency, and clogging and side reactions characteristic where the mass is heated wholly from the outside by a coal furnace as in the customary practice.

I am aware that it has been proposed to employ an electric arc across the reaction zone, but the same heat here was also simultaneously required to vaporize the sulphur at the reaction zone, and clogging difficulties and irregular burning of the carbon mass rendered the proposal inefi'ective. In the present process, the sulphur itself is a heat carrier and only the additional increment for reaction requires to be supplied by the electrical control direct in the reaction zone.

Other modes of applying the principle of the invention may be employed, change being made as regards the details disclosed, provided the steps stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctlv claim as my invention 1. The process of making carbon bisulphide, which comprises separately vaporizing sulphur outside the reaction zone, passing the sulphur vapor into contact with hot charcoal in the reaction zone while heating the charcoal to reaction temperature by pass ing an electric current through a mixture of said charcoal and conducting carbon, such conducting carbon being introduced sepa rately to the electrode zone to control the electrical resistance of the charge.

2. The process of making carbon bisulhide, which comprises separately vaporizmg sulphur and preheating the vapor thereof outside the reaction zone, passing such preheated vapor into contact with hot charcoal in the reaction zone while heating the charcoal to reaction temperature by passing an electric current through a mixture of said charcoal and conducting carbon, such conducting carbon being introduced separately to control the electrical resistance of the charge.

3. The process of making carbon bisulphide, which comprises passing sulphur vapor into contact with electrically heated charcoal, such sulphur vapor having been prepared by vaporizing sulphur by a sepa rate source of heat, and controlling the heat generated by electric current in the charcoal by introducing separately conducting-carbon in controlled amount to the electrode zone.

4. The process of making carbon bisulphide, which comprises separately vaporizing sulphur, passing the vapor thereof through a pass-way in a heating zone outside of the reaction zone, passing such vapor then into contact with hot charcoal in the reaction zone while heating the charcoal to reaction temperature by passing an electric current through a mixture of said charcoal and conducting-carbon, such conducting-carbon being introduced separately to the electrode zone to control the electric resistance of the charge.

5. The process of making carbon bisulphide, which comprises passing sulphur vapor through a pass-way in a heating zone outside the reaction zone, passing such vapor then into contact with electrically heated charcoal, such vapor having been prepared by a separate source of heat, and controlling the heat generated by the electric current in the charcoal by introducing separately conducting-carbon in controlled amount to the electrode zone.

Signed by me this 17th day of November,

HERBERT H. DOW. 

